Topic: CB750 K1 (72 title, 6/71 mfr plate) Need advice for elec ign, coils, carbs

[wwsummersjr]

Okay Guys, I'm old school (used to buy baskets & restore) & been out of the loop for decades. Bought a K1 & after spending bucks on new points, carb kit, plugs/resistor caps, etc, but ignition froggy, then not long after throwing a set of used coils on it, it soon just quit getting fire to plugs (fire at points). Tired of wasting my elderly time & need advice for aftermarket ignition/carburation sources. Help an old Geezer please!

[dusterdude]

Pamco ignition

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[wwsummersjr]

Thx Mark, I see you have a K1 as well. Any additional recommendations for coils, carbs?

[Johnie]

Clean and keep the OEM brass in the carbs. It can be done even if they are varnished from old gas. Here is a pic of my K3 carbs which are now sporting these same jets. Aftermarket carb kits are a bit different.

[BenelliSEI]

My K1 runs well on all the stuff you already bought. Check the old fuse block and make sure the main fuse is clean, and tight in the clips. That (or a worn out key switch) can give you some very weird ignition symptoms. Make sure the power feed to the coils is clean and consistent, before spending any more money. Good grounds to the frame and engine? Good luck.

[dusterdude]

Thx Mark, I see you have a K1 as well. Any additional recommendations for coils, carbs?

Not really,if you can find a good set of pd42's,the 1977 version,I would run those.I didn't care too much for the flattops that were original.on the coils,I'm running what I think are gl1000 coils and they work well.

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[PeWe]

If both coils do not fire anything, check the black-white wire from ign switch to both coils. It should be 12V here when ign on.

Even if advancer rotor is 180 degrees wrong/ blue, yellow from points swapped/ connected to wrong coil it should give occasional fire.
1:4- blue, 2:3- yellow

[wwsummersjr]

My gratitude to all for input! Carbs were gone through meticulously with new jets, etc., but I've slept a few times since then.... Wiring checked for voltage to coils, etc... My inclination is coils don't last forever & effing tired of timing points. Mark recommended Pamco elec/ign, but research also checking out Dynatek ign/coils/wires as a combo purchase.... Some ignition kits offer tuning via phone app, etc. Last 750 I built was a 74 engine in a Jammer hardtail frame in 1980 & used aftermarket coils/ electronic ignition, but cannot remember back that far. I cannot count the miles afterwards, Austin adventures,  including to State Capital for Helmet Run. Still want to improve carbs! Keep aware Bro's & watch out for cages!

[MauiK3]

Plug wire ends?
The caps go bad.

[wwsummersjr]

Resistor plug caps replaced after purchase. Bike ran, but still mid rpm flatline. Changed coils with spares had for decades, ran same for awhile, then nothing.